一項(xiàng)研究說(shuō),，到本世紀(jì)末,，CO2的增加可能導(dǎo)致幼魚被捕食者攻擊。在海水中,，CO2溶解并產(chǎn)生一種弱酸,，而科學(xué)家預(yù)計(jì)，在大氣CO2濃度高于目前將近百萬(wàn)分之390（ppm）的時(shí)候,，海洋表面水將變得更酸,。Philip Munday及其同事檢查了如果CO2濃度繼續(xù)以當(dāng)前的速率增加，那么本世紀(jì)可能發(fā)生的海洋酸性增加對(duì)幼魚的影響,。這組科學(xué)家把小丑魚和雀鯛幼魚放在CO2濃度為700ppm和850ppm的海水中,，然后觀察了這些魚對(duì)于捕食者氣味的反應(yīng)。
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這些作者說(shuō),，最初避開(kāi)這種氣味的魚的半數(shù)在700ppm和850ppm的海水中生活4天之后探測(cè)到這種氣味的能力更少,，所有這些幼魚看上去都變得被這種氣味所吸引。當(dāng)曾經(jīng)接觸到升高的CO2濃度的幼魚轉(zhuǎn)移到自然珊瑚礁棲息地中的時(shí)候,，這些魚在捕食者周圍用了更多的時(shí)間,，而且被吃掉的比率是對(duì)照組的5到9倍。這組作者說(shuō),，這項(xiàng)研究提示,，海洋酸化可能通過(guò)導(dǎo)致新孵化出的幼魚對(duì)周圍的捕食者更不警覺(jué)從而減少魚類的種群。(生物谷Bioon.net)
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.1004519107
Replenishment of fish populations is threatened by ocean acidification
Philip L. Mundaya,1, Danielle L. Dixsona, Mark I. McCormicka, Mark Meekanb, Maud C. O. Ferraric, and Douglas P. Chiversd
aAustralian Research Council Centre of Excellence for Coral Reef Studies and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia;
b Australian Institute of Marine Science, Perth, Western Australia 6009, Australia;
cDepartment of Environmental Science and Policy, University of California, Davis, CA 95616; and
dDepartment of Biology, University of Saskatchewan, SK, Canada S7N 5E2
There is increasing concern that ocean acidification, caused by the uptake of additional CO2 at the ocean surface, could affect the functioning of marine ecosystems; however, the mechanisms by which population declines will occur have not been identified, especially for noncalcifying species such as fishes. Here, we use a combination of laboratory and field-based experiments to show that levels of dissolved CO2 predicted to occur in the ocean this century alter the behavior of larval fish and dramatically decrease their survival during recruitment to adult populations. Altered behavior of larvae was detected at 700 ppm CO2, with many individuals becoming attracted to the smell of predators. At 850 ppm CO2, the ability to sense predators was completely impaired. Larvae exposed to elevated CO2 were more active and exhibited riskier behavior in natural coral-reef habitat. As a result, they had 5–9 times higher mortality from predation than current-day controls, with mortality increasing with CO2 concentration. Our results show that additional CO2 absorbed into the ocean will reduce recruitment success and have far-reaching consequences for the sustainability of fish populations.
